Back to results
US 8,078,272 B2Granted
Systems and methods for detecting or validating signals in the presence of noise
AssigneeCardiac Pacemakers, Inc.
InventorYayun Lin
Life of this patent
Estimating the term…
Abstract
Detecting or validating signals such as cardiac beats can be performed in the presence of myopotential or other noise. An amplitude peak, which can be a candidate for a detected beat, can be used in a normalized or other weighted average, along with a preceding and subsequent sample. The weighted average is compared to a noise threshold. Based on the result, the amplitude peak is either deemed an actual beat (e.g., depolarization or repolarization), or noise. The described systems, devices, and methods can improve the accuracy of detecting an actual beat in the presence of noise, during normal sinus rhythm or during an arrhythmia such as ventricular fibrillation. This, in turn, improves the accuracy with which therapy is delivered or withheld by an implantable device.
Claims28
A system comprising:
- a signal detector, comprising a detector input and comprising a detector output providing a physiologic sampled signal;
- and
- a signal processor circuit, coupled to the detector output, the signal processor circuit configured to distinguish, using a peak sample, a preceding sample to the peak sample, and a subsequent sample to the peak sample, a signal depolarization or repolarization from noise, and in which the signal processor circuit is configured to form a weighted average computed using as data points an amplitude of the peak sample from a baseline, an amplitude of the preceding sample from the same baseline, and an amplitude of the subsequent sample from the same baseline, wherein the preceding sample and the subsequent sample are specified adjustably according to a sample rate, and to distinguish a signal depolarization or repolarization from noise by comparing the weighted average to a specified threshold value.
An implantable cardiac rhythm management device comprising:
- a signal detector, comprising a signal detector input and comprising a signal detector output providing a physiologic sampled signal;
- and
- a depolarization or repolarization detector circuit, coupled to the first electrode, the depolarization or repolarization detector circuit including a level detector circuit configured to detect an intrinsic depolarization or repolarization on the intrinsic signal;
- and
- a signal processor circuit, coupled to the signal detector output and the depolarization or repolarization detector circuit, the signal processor circuit configured to validate the intrinsic depolarization or repolarization detected by the depolarization or repolarization detector circuit by distinguishing a depolarization or repolarization from noise, using a weighted average computed using as data points an amplitude, from a baseline, of a peak sample of the sampled signal, an amplitude, from the same baseline, of a preceding sample to the peak sample of the sampled signal, and an amplitude, from the same baseline, of a subsequent sample to the peak sample of the sampled signal, wherein the peak sample of the sampled signal is associated with a peak of the intrinsic depolarization or repolarization detected by the depolarization or repolarization detector circuit, and wherein the preceding sample and the subsequent sample are specified adjustably according to a sample rate.
2 more elements
A method comprising:
- sampling a physiological signal;
- detecting a peak sample from the signal;
- detecting a preceding sample to the peak sample from the signal;
- detecting a subsequent sample to the peak sample from the signal;
- distinguishing, using the peak sample, the preceding sample, and the subsequent sample, a depolarization or repolarization from noise, in which the distinguishing comprises:
- computing a weighted average, the statistic computed using as data points an amplitude of the peak sample from a baseline, an amplitude of the preceding sample from the same baseline, and an amplitude of the subsequent sample from the same baseline, wherein the preceding sample and the subsequent sample are specified adjustably according to a sample rate;
- and
- distinguishing a depolarization or repolarization from noise by comparing the weighted average to a specified threshold value.
5 more elements
A method comprising:
- detecting an intrinsic physiologic signal;
- detecting a depolarization or repolarization on the intrinsic signal by comparing a level of the intrinsic signal to a level threshold value to yield a level-detected depolarization or repolarization;
- sampling the intrinsic signal to produce a sampled signal;
- detecting a peak sample from the sampled signal, wherein the peak sample is associated with the level-detected depolarization or repolarization;
- detecting a preceding sample to the peak sample from the sampled signal;
- detecting a subsequent sample to the peak sample from the sampled signal;
- and
- validating, using the peak sample, the preceding sample, and the subsequent sample, the level-detected depolarization or repolarization by computing a weighted average using the peak sample, the preceding sample, and the subsequent sample, and comparing the weighted average to a noise threshold, wherein the preceding sample and the subsequent sample are specified adjustably according to a sample rate.
5 more elements
A system comprising:
- a physiologic signal detector, comprising a detector input and comprising a detector output providing a physiologic sampled signal;
- and
- a signal processor circuit, coupled to the detector output, the signal processor circuit configured to distinguish a depolarization or repolarization from noise, the distinguishing using an amplitude of a peak sample from a baseline, an amplitude, from the same baseline, of a preceding sample to the peak sample, and an amplitude, from the same baseline, of a subsequent sample to the peak sample, and in which the signal processor circuit is configured to form a weighted average of each of the amplitudes of the peak sample, the preceding sample, and the subsequent sample, and to distinguish a depolarization or repolarization from noise by comparing the weighted average to a specified threshold value, wherein the preceding sample and the subsequent sample are specified adjustably according to a sample rate.
Dependencies are inferred from the claim text.